Have you found many with the thermistor (Might be what you are calling the OL) going bad?

02-07-2013, 10:37 PM

LKJoel

Quote:

Originally Posted by 54regcab

Have you found many with the thermistor (Might be what you are calling the OL) going bad?

Yes, I am referring to the thermistor as an OL

02-07-2013, 10:54 PM

mark beiser

Quote:

Originally Posted by 54regcab

How many failures ahve you seen where the motor windings have failed vs. just the drive module?

On ECM2.x motors, my experience is that you will likely find at least 15-20 module only failures for each winding or bearing failure.
I find more winding failures than bearing failures.
Keep in mind that some failures that feel like bearing failures may actually be phase to phase shorts in the windings.
Phase to phase shorts in the windings cause the motor to magnetically lock up, and it can feel almost exactly like a seized up ball bearing when you try to turn the shaft.

I suspect that as time progresses, we will be finding more of them with bad bearings as units age.
The majority of VS blower equipped units in operation are less than 10 years old, a lot of brands didn't even have VS blower equipped units, or only had them in their very top tier equipment 10 years ago. Now there are manufacturers that have some sort of ECM motor in over half of their indoor equipment models.

02-08-2013, 03:09 AM

catmanacman

you will find more winding failures with the units that are in the down flow position

02-08-2013, 05:47 PM

Cool_Air

ecm motor failiur

Quote:

Originally Posted by Rodney28334

I know, I figured with all of the module failures that the suppliers would have figured out it would save every one (except motor manufacturer but motors are out sourced) time and money. I have never seen a ecm motor where it wasnt the module and most the failures have been a few years old. I havent replaced many lately so hopefully the got the problem at least contained.

:angel: Talking about ecm motors a few months back my wife started hearing something like a truck running outside while the ac was on, I open up the air handler and pull the blower out carried it to my shop and clean it. help for a little while i felt like the blower bracket was a little loose vibrating, but then the same sound started back a few days later. when the weather started getting cold the unit would kick off on hi head pressure in the the heat mode, I reset the breaker and it would run for awhile and kick off again,I ordered a replacement and install it and seems to be working find, I strigthen up the supple ducks with hard pipe 90° elbows and shorting the flex duct and getting a lot better air flow now, the motor that I pull out the bearings we tight, so this happen to be the motor and not the module this time, Im saving the module, I'm planning to in large one of my returns from a 12" to a 16" should help with lowing the static pressure. Now I will have two 16" returns I'll check the static on my system when I'm finish, hope its around 0.05.

02-08-2013, 08:59 PM

mark beiser

Quote:

Originally Posted by Cool_Air

:angel: Talking about ecm motors a few months back my wife started hearing something like a truck running outside while the ac was on, I open up the air handler and pull the blower out carried it to my shop and clean it. help for a little while i felt like the blower bracket was a little loose vibrating, but then the same sound started back a few days later. when the weather started getting cold the unit would kick off on hi head pressure in the the heat mode, I reset the breaker and it would run for awhile and kick off again,I ordered a replacement and install it and seems to be working find, I strigthen up the supple ducks with hard pipe 90° elbows and shorting the flex duct and getting a lot better air flow now, the motor that I pull out the bearings we tight, so this happen to be the motor and not the module this time, Im saving the module, I'm planning to in large one of my returns from a 12" to a 16" should help with lowing the static pressure. Now I will have two 16" returns I'll check the static on my system when I'm finish, hope its around 0.05.

Pop the module off and check the resistance wire to wire(phase to phase) of the motor windings.
From your description of the sound like a "truck running outside", the low airflow due to reduced blower speed, and the "tight" bearings, I predict that you will find that the resistances are not the same due to a phase to phase short in the windings.

A phase to phase short will make the motor try to lock up magnetically, and if it runs at all, it will make noise, and run slow.
The last one I found with a phase to phase short, the customer described the noise as sounding like a propeller driven airplane in the distance.